Written in Latin for students at the Gregorian University in Rome, Bernard Lonergan's De Deo Trino (The Triune God) is a monumental two-part examination of trinitarian theology published initially in 1961 and again, in revised form, in 1964. The first part, the pars dogmatica, is here translated into English in an edition that includes the original Latin on facing pages. The work begins with the Prolegomena, which traces the dialectical development...